CVE-2013-6404 in IRC
Summary
by MITRE
Quassel core (server daemon) in Quassel IRC before 0.9.2 does not properly verify the user ID when accessing user backlogs, which allows remote authenticated users to read other users backlogs via the bufferid in (1) 16/select_buffer_by_id.sql, (2) 16/select_buffer_by_id.sql, and (3) 16/select_buffer_by_id.sql in core/SQL/PostgreSQL/.
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Analysis
by VulDB Data Team • 12/23/2024
The vulnerability identified as CVE-2013-6404 affects Quassel IRC core server daemon versions prior to 0.9.2, representing a critical authorization flaw that undermines the security model of the messaging system. This issue specifically targets the PostgreSQL database backend implementation where user access controls fail to properly validate user identities when retrieving historical chat messages. The vulnerability manifests through three identical SQL query files located in the core/SQL/PostgreSQL/ directory, suggesting a systemic code duplication error that propagates the authorization bypass across multiple database access points. The flaw enables authenticated attackers to exploit the buffer ID parameter within SQL queries to access chat histories belonging to other users without proper authorization.
The technical mechanism of this vulnerability stems from insufficient input validation and user context verification within the Quassel core's database access layer. When authenticated users submit requests to retrieve chat buffer information, the system fails to cross-reference the requesting user's credentials against the target buffer's ownership information. This allows an attacker to manipulate the bufferid parameter in the SQL queries to reference buffers belonging to other users, effectively bypassing the intended access controls. The vulnerability is classified as a privilege escalation issue under CWE-285, specifically relating to improper authorization within database access controls. The three identical SQL files indicate that the flaw exists in multiple locations within the codebase, suggesting either poor code organization or a lack of proper security review processes during development.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables persistent surveillance and potential data exfiltration capabilities for authenticated attackers. Remote authenticated users can systematically access chat histories, private conversations, and potentially sensitive information shared within the IRC network without detection. This compromise undermines the fundamental security assumptions of user privacy and message confidentiality that IRC systems rely upon for secure communication. The vulnerability affects all users of Quassel IRC servers running versions before 0.9.2, making it particularly dangerous in environments where users may have varying levels of trust or where the system serves as a communication platform for sensitive discussions. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation and credential access tactics, enabling adversaries to maintain persistent access to historical communications data.
Mitigation strategies for CVE-2013-6404 require immediate deployment of Quassel core version 0.9.2 or later, which contains the necessary authorization fixes. Organizations should implement comprehensive patch management procedures to ensure all Quassel installations are updated promptly. Additionally, administrators should review and audit existing user access controls, implement proper logging of database access patterns, and monitor for unusual buffer access requests that may indicate exploitation attempts. The vulnerability highlights the importance of proper input validation and user context verification in database access layers, emphasizing that authentication alone is insufficient without proper authorization checks. Security teams should also consider implementing network-level monitoring to detect anomalous SQL query patterns that could indicate exploitation of similar authorization bypass vulnerabilities in other systems.